Chris we must remember we are all human, we are all created the same but we all have learned (or not) differently, each of our own experiences are different, no two people will do the same job the same way, this in it self can contribute to a job going faster or slower, but I find sometimes letting a person to at least try it their way, then I become the teacher to meld them into trying ways to allow them to use their skills but to add to them to make the job go faster, this can be from scraping their way to just adding some pointers that will make it a little easier, the experience that we may have can be a learning tool for others if we present it in a non belittling learning way. we all want to be a important individualized person that matters.
So when we want to apply our experience to help others to learn new ways, we must remember that everyone wants to feel important to the job at hand, but as a supervisor we also must let them understand that when things are not being preformed in a timely manner they must also be open minded to learn new ways and or adjust to different thinking that can help the job not only go faster but more smoothly and easier, this is what team work is about, two guys who can put their heads together create a job into a production line, each taking a part of the work to complete.
One of the best teachers is by sight plus hands on, this is where we sometimes need to show them how its done or at least give them an idea that they can add to or take away from as long as it gets the job done in the expected time.
As others have said yelling is not only non productive, it tell the receiver of the yelling you have lost control, always keep you calm, always be in-control, learn to be a teacher as if it is your own children you are dealing with, never expect a person to have all the answers and that they can convey this to you, most who have a pride will be embarrassed to admit not knowing things, but if you approach a worker in a very open minded way that you are open to their thoughts and you expect the same in return, and let them know that you want them to ask any time they need to, you will find that they want to learn, to better themselves, of course this can be a point where you can also weed out those who can be stubborn that have closed minds, who think they know it all, but for the most part most all of us want to learn.
Its all in how you present it to the worker.